Messages in this thread | | | Subject | Re: [RFC PATCH v2 1/7] x86/paravirt: Add pv_idle_ops to paravirt ops | From | Juergen Gross <> | Date | Wed, 30 Aug 2017 09:33:52 +0200 |
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On 29/08/17 15:55, Konrad Rzeszutek Wilk wrote: > On Tue, Aug 29, 2017 at 11:46:35AM +0000, Yang Zhang wrote: >> So far, pv_idle_ops.poll is the only ops for pv_idle. .poll is called in >> idle path which will polling for a while before we enter the real idle >> state. >> >> In virtualization, idle path includes several heavy operations >> includes timer access(LAPIC timer or TSC deadline timer) which will hurt >> performance especially for latency intensive workload like message >> passing task. The cost is mainly come from the vmexit which is a >> hardware context switch between VM and hypervisor. Our solution is to >> poll for a while and do not enter real idle path if we can get the >> schedule event during polling. >> >> Poll may cause the CPU waste so we adopt a smart polling mechanism to >> reduce the useless poll. >> >> Signed-off-by: Yang Zhang <yang.zhang.wz@gmail.com> >> Signed-off-by: Quan Xu <quan.xu0@gmail.com> >> Cc: Jeremy Fitzhardinge <jeremy@goop.org> >> Cc: Chris Wright <chrisw@sous-sol.org> >> Cc: Alok Kataria <akataria@vmware.com> >> Cc: Rusty Russell <rusty@rustcorp.com.au> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: Ingo Molnar <mingo@redhat.com> >> Cc: "H. Peter Anvin" <hpa@zytor.com> >> Cc: x86@kernel.org >> Cc: Peter Zijlstra <peterz@infradead.org> >> Cc: Andy Lutomirski <luto@kernel.org> >> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> >> Cc: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> >> Cc: Kees Cook <keescook@chromium.org> >> Cc: virtualization@lists.linux-foundation.org >> Cc: linux-kernel@vger.kernel.org > > Adding xen-devel. > > Juergen, we really should replace Jeremy's name with xen-devel or > your name..
I wouldn't mind being added. What does Jeremy think of being removed?
> Wasn't there an patch by you that took some of the > mainternship over it?
I added include/linux/hypervisor.h to the PARAVIRT section and offered to maintain it in case the PARAVIRT maintainers didn't want to.
Juergen
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